Apparatus and Method for Manufacturing Secondary Battery

ABSTRACT

An apparatus for manufacturing a secondary battery includes: a recess induction part configured to allow a folding part folded in a battery case of a secondary battery to be recessed inward so as to provide a recess part when the battery case of the secondary battery is folded; a first guide, of which one side of one end is recessed to define a concave space, wherein, when the battery case of the secondary battery is folded, the one end is configured to be inserted into the battery case to push the folding part to an outside so that the recess induction part is configured to be inserted into the concave space; and a second guide configured to hold a sealing part of the battery case so as to fix the battery case.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase entry under 35 U.S.C. § 371of International Application No. PCT/KR2020/004428, filed Mar. 31, 2020,published in Korean, which claims the benefit of the priority of KoreanPatent Application No. 10-2019-0067388, filed on Jun. 7, 2019, both ofwhich are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to an apparatus and method formanufacturing a secondary battery, and more particularly, to anapparatus and method for manufacturing a secondary battery which arecapable of reducing a size error and increasing a ratio of an energydensity to a volume.

BACKGROUND ART

In general, secondary batteries include nickel-cadmium batteries,nickel-hydrogen batteries, lithium ion batteries, and lithium ionpolymer batteries. Such a secondary battery is being applied to and usedin small-sized products such as digital cameras, P-DVDs, MP3Ps, mobilephones, PDAs, portable game devices, power tools, E-bikes, and the likeas well as large-sized products requiring high power such as electricvehicles and hybrid vehicles, power storage devices for storing surpluspower or renewable energy, and backup power storage devices.

In order to manufacture an electrode assembly, a cathode, a separator,and an anode are manufactured and stacked. Specifically, cathode activematerial slurry is applied to a cathode collector, and anode activematerial slurry is applied to an anode collector to manufacture acathode and an anode. Also, when the separator is interposed and stackedbetween the manufactured cathode and anode, unit cells are formed. Theunit cells are stacked on each other to form an electrode assembly.Also, when the electrode assembly is accommodated in a specific case,and an electrolyte is injected, the secondary battery is manufactured.

Such a secondary battery is classified into a pouch type secondarybattery and a can type secondary battery according to a material of abattery case accommodating an electrode assembly. In the pouch typesecondary battery, the electrode assembly is accommodated in a pouchmade of a flexible polymer material having a variable shape. Also, inthe can type secondary battery, an electrode assembly is accommodated ina case made of a metal or plastic material having a predetermined shape.

The pouch type battery case is manufactured by performing drawingmolding on a pouch film having flexibility to form a cup part. Thedrawing molding is performed by inserting a pouch film into a press andapplying a pressure to the pouch film through a punch to stretch thepouch film. In addition, when the cup part is formed, an electrodeassembly is accommodated in an accommodation space of the cup part, andthen, the battery case is folded to seal a sealing part, therebymanufacturing a secondary battery.

When the cup part is molded in the pouch film, two cup parts may bedrawn and molded to be symmetrical to each other in one pouch film.Also, the electrode assembly may be accommodated in the accommodationspace of the cup part, and then, the battery case may be folded so thatthe two cup parts face each other. As a result, since the two cup partsaccommodate the one electrode assembly, the electrode assembly has athickness T thicker than that of an electrode assembly accommodated inonly one cup part. Also, since the battery case is folded to form oneedge of the secondary battery, only three edges except for the one edgemay be sealed when a sealing process is performed later. Thus, thenumber of edges to be sealed may be reduced to improve a process rateand reduce the number of trimming processes.

FIG. 1 is a plan view of a pouch type secondary battery 3 according tothe related art.

When a battery case is folded, and heat and a pressure are applied toseal the battery case, a portion of a folded edge of the secondarybattery 3, i.e., a portion of a folding part 336, protrudes to theoutside. This is called a bat ear 2.

As illustrated in FIG. 1, when the bat ear 2 protrudes, an unnecessaryvolume further increases, and thus an error occurs in a designed size ofthe secondary battery 3. Thus, when assembling the secondary batteries 3to manufacture a battery module or the like, there is a problem in thatit is not easy to assembly the secondary batteries 3, and each of thesecondary batteries 3 has to be designed with a small size from thebeginning. Also, since the volume of the secondary battery 3 increasesas a whole, there is also a problem in that a ratio of the energydensity to the volume decreases.

DISCLOSURE OF THE INVENTION Technical Problem

An object to be achieved by the present invention is to provide anapparatus and method for manufacturing a secondary battery, which arecapable of reducing an error in size and increasing a ratio of an energydensity to a volume.

The objects of the present invention are not limited to theaforementioned object, but other objects not described herein will beclearly understood by those skilled in the art from descriptions below.

Technical Solution

An apparatus for manufacturing a secondary battery according to anembodiment of the present invention for achieving the above objectincludes: a recess induction part configured to allow a folding partfolded in a battery case of a secondary battery to be recessed inward soas to provide a recess part when the battery case of the secondarybattery is folded; a first guide, of which one side of one end isrecessed to define a concave space, wherein, when the battery case ofthe secondary battery is folded, the one end is configured to beinserted into the battery case to push the folding part to an outside sothat the recess induction part is configured to be inserted into theconcave space; and a second guide configured to hold a sealing part ofthe battery case so as to fix the battery case.

In addition, the recess induction part may include a plurality of recessinduction parts configured to move linearly in a direction parallel to adirection toward each other.

In addition, the first guide may be inserted into the battery casethrough the sealing part before the sealing part is sealed.

In addition, when the first guide pushes the folding part to theoutside, the folding part may be inserted into the concave spacetogether with the recess induction part to define a recess part.

In addition, in the first guide, the one side of the one end may berecessed inward to be filleted.

In addition, in the first guide, the one side of the one end may berecessed inward and filleted to define the concave space with aplurality of planes, and an exterior angle defined by the plurality ofplanes may be provided as an obtuse angle.

In addition, the apparatus may further include a sealing tool configuredto apply heat and a pressure to the sealing part to seal the sealingpart.

In addition, before the sealing part is sealed, the first guide may bepulled out from the battery case.

In addition, the first guide may have a thickness less a thickness ofthe battery case that when the battery case is folded.

In addition, the second guide may have a forceps shape so that it isconfigured to hold the sealing part from opposing surfaces.

A method for manufacturing a secondary battery according to anembodiment of the present invention for achieving the above objectincludes: accommodating an electrode assembly, in which electrodes andseparators are alternately stacked, in a battery case; recessing afolding part folded in the battery case inward with a recess inductionpart to form a recess part when the battery case is folded; of insertingone end of a first guide, of which one side of the one end is recessedto form a concave space, into the battery case; pushing the folding partof the battery case to an outside with the first guide so that therecess induction part is inserted into the concave space; fixing thebattery case by holding a sealing part of the battery case with a secondguide; and sealing the sealing part by applying heat and a pressure tothe sealing part with a sealing tool.

In addition, the method may further include, after the step of fixingthe battery case and before the step of sealing the sealing part, a stepof pulling out the first guide from the battery case.

A secondary battery according to an embodiment of the present inventionfor achieving the above object is manufactured through the method formanufacturing the secondary battery.

Particularities of other embodiments are included in the detaileddescription and drawings.

Advantageous Effects

The embodiments of the present invention may have at least the followingeffects.

The formation of the bat ear may be prevented to reduce the erroroccurring in the designed size of the secondary battery, and thesecondary batteries may be easily assembled to manufacture the batterymodule.

In addition, since the unnecessary volume of the secondary batterydecreases as a whole, a ratio of the energy density to the volume mayincrease.

The effects of the prevent invention are not limited by theaforementioned description, and thus, more varied effects are involvedin this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a pouch type secondary battery according to arelated art.

FIG. 2 is an assembly view of a pouch type secondary battery accordingto an embodiment of the present invention.

FIG. 3 is a perspective view of the pouch type secondary batteryaccording to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a pouch type battery case, takenalong line A-A′ of FIG. 2, according to an embodiment of the presentinvention.

FIG. 5 is a cross-sectional view illustrating a state in which anelectrode assembly is being accommodated in the pouch type battery caseof FIG. 4.

FIG. 6 is a cross-sectional view illustrating a state in which theelectrode assembly is accommodated in the pouch type battery case ofFIG. 4.

FIG. 7 is a cross-sectional view illustrating a state in which the pouchtype battery case of FIG. 4 is being folded.

FIG. 8 is a cross-sectional view illustrating a state in which the pouchtype battery case of FIG. 4 is folded.

FIG. 9 is a flowchart illustrating a method for manufacturing asecondary battery according to an embodiment of the present invention.

FIG. 10 is a schematic view illustrating a state in which a recessinduction part and the battery case are close to each other according toan embodiment of the present invention.

FIG. 11 is a schematic view illustrating a state in which a first guideis being inserted into the pouch type battery case according to anembodiment of the present invention.

FIG. 12 is a schematic view of the first guide according to anembodiment of the present invention.

FIG. 13 is a schematic view of a first guide according to anotherembodiment of the present invention.

FIG. 14 is a schematic view illustrating a state in which a second guideis holding a sealing part of the pouch type battery case according to anembodiment of the present invention.

FIG. 15 is a schematic view illustrating a state in which the firstguide is being pulled out from the pouch type battery case according toan embodiment of the present invention.

FIG. 16 is a schematic view illustrating a state in which a sealing toolseals a sealing part of the pouch type battery case according to anembodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

Advantages and features of the present invention, and implementationmethods thereof will be clarified through following embodimentsdescribed with reference to the accompanying drawings. The presentinvention may, however be embodied in different forms and should not beconstrued as limited to the embodiments set forth herein. Rather, theseembodiments are provided so that this disclosure will be thorough andcomplete, and will fully convey the scope of the present invention tothose skilled in the art. Further, the present invention is only definedby scopes of claims. Like reference numerals refer to like elementsthroughout.

Unless terms used in the present invention are defined differently, allterms (including technical and scientific terms) used herein have thesame meaning as generally understood by those skilled in the art. Also,unless defined clearly and apparently in the description, the terms asdefined in a commonly used dictionary are not ideally or excessivelyconstrued as having formal meaning.

In the following description, the technical terms are used only forexplaining a specific exemplary embodiment while not limiting thepresent invention. In this specification, the terms of a singular formmay include plural forms unless specifically mentioned. The meaning of“comprises” and/or “including” does not exclude other components besidesa mentioned component.

Hereinafter, preferred embodiments will be described in detail withreference to the accompanying drawings.

FIG. 2 is an assembly view of a pouch type secondary battery 1 accordingto an embodiment of the present invention, and FIG. 3 is a perspectiveview of the pouch type secondary battery 1 according to an embodiment ofthe present invention.

As illustrated in FIG. 2, the pouch type secondary battery 1 accordingto an embodiment of the present invention includes a pouch type batterycase 13 and an electrode assembly 10 accommodated in the battery case13.

The electrode assembly 10 may be a stacked structure including twoelectrodes such as a cathode and an anode and a separator interposedbetween the electrodes to insulate the electrodes from each other ordisposed at a left or right side of one electrode. The stacked structuremay have various shapes without being limited in shape. For example, thecathode and the anode, each of which has a predetermined standard, maybe stacked with the separator therebetween, or the stacked structure maybe wound in the form of a jelly roll. Each of the two electrodes has astructure in which active material slurry is applied to a metal foil ora mesh-shaped collector including aluminum and copper. The slurry may beusually formed by agitating a granular active material, an auxiliaryconductor, a binder, and a plasticizer with a solvent added. The solventmay be removed in the subsequent process.

As illustrated in FIG. 2, the electrode assembly 10 includes theelectrode tabs 11. The electrode tabs 11 are respectively connected to apositive electrode and a negative electrode of the electrode assembly 10to protrude to the outside of the electrode assembly 10, therebyproviding a path, through which electrons are moved, between the insideand outside of the electrode assembly 10. A collector of the electrodeassembly 10 is constituted by a portion coated with an electrode activematerial and a distal end, on which the electrode active material is notapplied, i.e., a non-coating portion. Also, each of the electrode tabs11 may be formed by cutting the non-coating portion or by connecting aseparate conductive member to the non-coating portion through ultrasonicwelding. As illustrated in FIG. 2, the electrode tabs 11 may protrude ineach of different directions of the electrode assembly 10, but is notlimited thereto. For example, the electrode tabs may protrude inparallel to each other from one side in the same direction.

In the electrode assembly 10, the electrode lead 12 is connected to theelectrode tab 11 through spot welding. Also, a portion of the electrodelead 12 is surrounded by an insulation part 14. An insulation part 14may be disposed to be limited within a sealing part 134, at which afirst case 131 and a second case 132 are thermally fused, so as to bebonded to the battery case 13. Also, electricity generated from theelectrode assembly 10 may be prevented from flowing to the battery case13 through the electrode lead 12, and the sealing of the battery case 13may be maintained. Thus, the insulation part 14 may be made of anonconductor having non-conductivity, which is not electricallyconductive. In general, although an insulation tape which is easilyattached to the electrode lead 12 and has a relatively thin thickness ismainly used as the insulation part 14, the present invention is notlimited thereto. For example, various members may be used as theinsulation part 14 as long as the members are capable of insulating theelectrode lead 12.

The electrode lead 12 may extend in different directions or extend inthe same direction according to the formation positions of the positiveelectrode tab 111 and the negative electrode tab 112. The positiveelectrode lead 121 and the negative electrode lead 122 may be made ofmaterials different from each other. That is, the cathode lead 121 maybe made of the same material as the cathode plate, i.e., an aluminum(Al) material, and the anode lead 122 may be made of the same materialas the anode plate, i.e., a copper (Cu) material or a copper materialcoated with nickel (Ni). Also, a portion of the electrode lead 12, whichprotrudes to the outside of the battery case 13, may be provided as aterminal part and electrically connected to an external terminal.

The battery case 13 is a pouch made of a flexible material and ismanufactured by performing drawing molding on the pouch film havingflexibility to form a cup part 133. Also, the battery case 13accommodates the electrode assembly 10 so that a portion of theelectrode lead 12, i.e., the terminal part is exposed and then issealed. As illustrated in FIG. 2, the battery case 13 includes a firstcase 131 and a second case 132. A first cup part 1331 and a second cuppart 1332 are respectively provided in the first case 131 and the secondcase 132 to provide an accommodation space in which the electrodeassembly 10 is accommodated. Also, the battery case is folded to allowthe electrode assembly 10 to be accommodated in the accommodation spaceof the cup part 133, thereby preventing the electrode assembly 10 frombeing separated to the outside of the battery case 13.

When the two cup parts 133 are drawn and molded to be symmetrical toeach other in the pouch film, an accommodation part 135 may be drawn andmolded together between the two cup parts 133. As illustrated in FIG. 2,the accommodation part 135 is a space which is lengthily defined in alongitudinal direction of edges of the first cup part 1331 and thesecond cup part 1332, which face each other, and in which the electrodeassembly 10 is accommodated first, between the first cup part 1331 andthe second cup part 1332. The accommodation part 135 accommodates oneside of the electrode assembly 10 first to fix a position of the oneside of the electrode assembly 10 so that the electrode assembly 10 iseasily accommodated in the cup part 133. For this, as illustrated inFIG. 2, the accommodation part 135 has a width W and length I, whichrespectively correspond to a thickness T and length L of the electrodeassembly 10 and is disposed at a position spaced the same distance fromthe first cup part 1331 and the second cup part 1332. Thus, a centralaxis defined in a longitudinal direction of the accommodation part 135functions as a symmetrical axis of the first cup part 1331 and thesecond cup part 1332.

When the electrode lead 12 is connected to the electrode tab 11 of theelectrode assembly 10, and the insulation part 14 is disposed on aportion of the electrode lead 12, the electrode assembly 10 isaccommodated in the accommodation part 135. Also, when the first case131 and the second case 132 are folded, the electrode assembly 10 isaccommodated in the accommodation space provided in the first and secondcup parts 1331 and 1332, and then, the first and second cup parts 1331and 1332 surround the electrode assembly 10. Also, an electrolyte isinjected into the accommodation space, and sealing parts 134 disposed onedges of the first case 131 and the second case 132 are sealed. Theelectrolyte may move lithium ions generated by electrochemical reactionof the electrode during charging and discharging of the secondarybattery 1. The electrolyte may include a non-aqueous organic electrolytethat is a mixture of a lithium salt and a high-purity organic solvent ora polymer using a polymer electrolyte. As illustrated in FIG. 3, thepouch type secondary battery 1 may be manufactured through theabove-described method.

FIG. 4 is a cross-sectional view of the pouch type battery case 13,taken along line A-A′ of FIG. 2, according to an embodiment of thepresent invention.

As illustrated in FIG. 4, the cup part 133 has a shape in which a depthd gradually increases from a portion 1333 corresponding to a centralportion of the width W of the electrode assembly 10 toward a portion1334 corresponding to an upper edge of the electrode assembly 10. Also,a section between the accommodation part 135 and the cup part 133 has aflat shape with little change in depth.

The deepest depth d in the cup part 133 is a portion corresponding tothe upper edge of the electrode assembly 10, and the depth d ispreferably deeper than half of the thickness T of the electrode assembly10. Thereafter, when the first and second cup parts 1331 and 1332 faceeach other, and the sealing parts 134 of the battery case 13 are sealed,the cup part 133 accommodates the electrode assembly 10 therein.However, if the depth d of each of the first cup part 1331 and thesecond cup part 132 is not deeper than half of the thickness T of theelectrode assembly 10, after the first cup part 1331 and the second cuppart 1332 accommodate the electrode assembly 10 therein, the sealingparts 134 may not contact each other so as not to be sealed, or even ifthe sealing parts contact each other, a contact area is too narrow tocause sealing failure.

A section between the accommodation part 135 and the cup part 133 has alength S that varies according to the width W and thickness T of theelectrode assembly 10. That is, it is preferable that the shorter thewidth W of the electrode assembly 10, the shorter the length S of thesection between the accommodation part 135 and the cup part 133. On theother hand, it is preferable that the longer the width W of theelectrode assembly 10, the longer the length S of the section betweenthe accommodation part 135 and the cup part 133. Also, since the thickerthe thickness T of the electrode assembly 10, the deeper the depth d ofthe cup part 133, it is preferable that that the length S of the sectionbetween the accommodation part 135 and the cup part 133 is shortened. Onthe other hand, since the thinner the thickness T of the electrodeassembly 10, the shallower the depth d of the cup part 133, it ispreferable that the length S of the section between the accommodationpart 135 and the cup part 133 is longer.

FIG. 5 is a cross-sectional view illustrating a state in which theelectrode assembly 10 is being accommodated in the pouch type batterycase 13 of FIG. 4, and FIG. 6 is a cross-sectional view illustrating astate in which the electrode assembly 10 is accommodated in the pouchtype battery case 13 of FIG. 4.

The accommodation part 135 accommodates one side of the electrodeassembly 10. Here, as illustrated in FIGS. 2 and 5, it is preferablethat the electrode assembly 10 is accommodated upright from the top tothe bottom. Thus, when the battery case 13 is folded later, the firstand second cup parts 1331 and 1332 respectively disposed on both sidesof the electrode assembly 10 may surround the electrode assembly 10 toaccommodate the electrode assembly 10 therein.

As described above, since the accommodation part 135 has the width W andlength I, which respectively correspond to the thickness T and length Lof the electrode assembly 10, as illustrated in FIG. 6, the electrodeassembly 10 may be easily accommodated in the accommodation part 135 andthen fixed in position.

FIG. 7 is a cross-sectional view illustrating a state in which the pouchtype battery case 13 of FIG. 4 is being folded, and FIG. 8 is across-sectional view illustrating a state in which the pouch typebattery case 13 of FIG. 4 is folded.

After the electrode assembly 10 is accommodated in the accommodationpart 135, the first case 131 and the second case 132, which arerespectively disposed at both sides of the accommodation part 135, arefolded upward as illustrated in FIG. 7. As a result, as illustrated inFIG. 8, the two cup parts 133 may face each other to surround theelectrode assembly 10 so that the electrode assembly 10 is accommodatedin the accommodation space provided in the cup parts 133.

The first case 131 and the second case 132 are bent from both sidewallsthat define the accommodation part 135 and then connected to each other,respectively. Also, when the first case 131 and the second case 132 arefolded, the first and second cases 131 and 132, which are bent, areunfolded from both the sidewalls to accommodate the electrode assembly10 in the cup parts 133. That is, the battery case 13 is folded whenviewed as a whole, but the bent portion is unfolded when viewed fromboth the sidewalls of the accommodation part 135.

As described above, after the first case 131 and the second case 132 arefolded, when the sealing part 134 is sealed using a sealing tool 23 (seeFIG. 16), the secondary battery 1 is completely manufactured.

FIG. 9 is a flowchart illustrating a method for manufacturing thesecondary battery 1 according to an embodiment of the present invention.

As described above, in the related art, when the battery case 13 isfolded, and heat and a pressure are applied to the sealing part 134 toseal the sealing part 134, a portion of the folding part 336 protrudesto the outside to form a bat ear 2. Thus, since an unnecessary volume ofthe secondary battery 3 increases, an error occurs in a designed size.Also, when assembling the secondary batteries 3 to manufacture a batterymodule or the like, there is a problem in that it is not easy toassemble the secondary batteries 3, and each of the secondary batteries3 has to be designed with a small size from the beginning. Also, sincethe volume of the secondary battery 3 increases as a whole, there isalso a problem in that a ratio of the energy density to the volumedecreases.

Here, the folding part 136 refers to an area formed to extend in alongitudinal direction of an accommodation part 135 from both ends ofthe accommodation part 135. Also, the folding part 136 is a portion thatis folded from each of both ends of the accommodation part 135 in thebattery case 13 when the battery case 13 is folded and constitutes aportion of the sealing part 134.

According to an embodiment of the present invention, a portion 1361 ofthe folding part 136, which has formed as the bat ear 2, may be arrangedby a first guide 21 so as not to protrude to the outside. Thus, theformation of the bat ear 2 may be prevented to reduce the erroroccurring in the designed size of the secondary battery 1, and thesecondary batteries 1 may be easily assembled to manufacture the batterymodule. Also, since the secondary battery 1 is unnecessarily reduced involume as a whole, energy density to a volume may increase.

For this, the method for manufacturing the secondary battery 1 accordingto an embodiment of the present invention includes: a step ofaccommodating an electrode assembly 10, in which electrodes andseparators are alternately stacked, in a battery case 13 of thesecondary battery 1; a step of allowing a plurality of recess inductionparts 20 to recess a folding part 136 folded in the battery case 13inward to form a recess part 1362 when the battery case 13 is folded; astep of inserting one end 211 (see FIG. 12) of a first guide 21, ofwhich one side of the one end 211 is recessed to form a concave space212 (see FIG. 12), into the battery case 13; a step of allowing thefirst guide 21 to push a folding part 136 of the battery case 13 to theoutside so that each of the recess induction parts 20 is inserted intothe concave space 211; a step of allowing a second guide 22 to hold asealing part 134 of the battery case 13 so as to fix the battery case13; and a step of allowing a sealing tool 23 to apply heat and apressure to the sealing part 135 so as to seal the sealing part 134.

Hereinafter, each of the steps illustrated in the flowchart of FIG. 9will be described with reference to FIGS. 10 to 16.

FIG. 10 is a schematic view illustrating a state in which a recessinduction part 20 and the battery case 13 are close to each otheraccording to an embodiment of the present invention.

An apparatus for manufacturing a secondary battery 1 according to anembodiment of the present invention includes: a recess induction part 20configured to allow a folding part 136 folded in a battery case 13 to berecessed inward so as to provide a recess part 1362 when the batterycase 13 of the secondary battery 1 is folded; a first guide 21, of whichone side of one end 211 is recessed to define a concave space 212 andinto which the one end 211 is inserted into the battery case 13 to pushthe folding part 136 to the outside so that the recess induction part 20is inserted into the concave space 212; and a second guide 22 configuredto hold a sealing part 134 of the battery case 13 so as to fix thebattery case 13. Also, the apparatus for manufacturing the secondarybattery 1 may further include a sealing tool 23 that seals the sealingpart 134 by applying heat or a pressure to the sealing part 134.

First, an electrode assembly 10 in which electrodes and separators arealternately stacked is accommodated in the battery case 13 (S901). Whenthe battery case 13 is folded, before the sealing part 134 is sealed,the recess induction part 20 recesses the folding part 136 folded in thebattery case 13 inward (S902). Thus, a recess part 1362 may be definedin the battery case 13.

The recess induction part 20 recesses the folding part 136 folded in thebattery case 13 inward to define the recess part 1362. Here, the recessguide part 20 is easy to move. Thus, the recess guide part 20 may movetoward the battery case 13. Alternatively, as illustrated in FIG. 10,the recess guide part 20 is fixed to a separate mechanism, and thebattery case 13 may move toward the recess guide part 20. For example,if the battery case 13 is mounted on a worktable or a table (not shown)to perform an operation with the first guide 21 and the second guide 22on the battery case 13 later, the recess induction part 20 may be fixedto one surface of the worktable or the table (not shown) to protrude.Alternatively, a separate stand may be fixed to the worktable or thetable (not shown), and the recess guide unit 20 may be fixed to thisstand (not shown). That is, if the recess induction part 20 is fixed,various methods may be used without limitation.

As illustrated in FIG. 10, the battery case 13 moves closer to the fixedrecess guide part 20. Here, the folding part 136 of the battery case 13is disposed in a direction toward the recess induction part 20. Also,the battery case 13 is pushed toward the fixed recess guide part 20.Then, the folding part 136 of the pouch type secondary battery 13 havingflexibility may be recessed inward by a reaction of the fixed recessinduction part 20.

As illustrated in FIG. 10, the recess induction part 20 may have acylindrical shape, but is not limited thereto. For example, the recessinduction part 20 may have various shapes such as a triangular pillar, asquare pillar, and an elliptical pillar as long as the recess inductionpart 20 provides the recess part 1362. However, the shape of the recesspart 1362 corresponds to that of the recess induction part 20. Thus, theshape of the recess part 1362 may variously vary according to the shapeof the recess induction part 20.

The battery case 13 may generally include the folding parts 136 on bothsides thereof. Thus, the recess parts 1362 may be disposed on both thefolding parts 136, respectively. For this, the recess induction part 20may be provided in plurality to push each of both the folding parts 136of the battery case 13 toward the recess induction part 20 so as toprovide the recess part in one operation.

Here, a distance between the plurality of recess parts 1362 to bedefined in the battery case 13 and a distance between the plurality ofrecess induction parts 20 correspond to each other. However, since asize of the battery case 13 is different according to a model, standard,and the like of the secondary battery 1, the distance between theplurality of recess parts 1362 may not be constant. Therefore, theplurality of recess guide parts 20 may move in a straight line in adirection parallel to a direction toward each other. As a result, thedistance between the plurality of recess induction parts 20 may vary tocorrespond to the distance between the plurality of recess parts 1362.

However, the present invention is not limited thereto, and only onerecess guide part 20 may be provided, and both the folding parts 136 maybe sequentially pushed toward the recess induction part 20 to performthe operation of forming the recess part 1362 twice.

FIG. 11 is a schematic view illustrating a state in which the firstguide 21 is being inserted into the pouch type battery case 13 accordingto an embodiment of the present invention, and FIG. 12 is a schematicview of the first guide 21 according to an embodiment of the presentinvention.

After the recess part 1362 is defined, as illustrated in FIG. 11, beforethe sealing part 134 is sealed, the first guide 21 is inserted into thebattery case 13 through the sealing part 134 (S903). Here, the firstguide 21 has a bar shape, and one side of one end 211 of the first guide21 is recessed inward to define the concave space 212. The first guide21 is inserted into the battery case 13 so that the recessed one end 211faces the inside of the battery case 13.

Particularly, in the first guide 21 according to an embodiment of thepresent invention, as illustrated in FIG. 12, it is preferable that theone side of the one end 211 is filleted inward. As a result, one side ofthe one end 211 defines the concave space 212 with a curved surface, andwhen the one end 211 pushes the folding part 136 of the battery case 13outward, the folding part 136 is inserted into the concave space 212together with the recess induction part 20. Therefore, the shape of theformed recess part 1362 may be firmed.

FIG. 13 is a schematic view of a first guide 21 a according to anotherembodiment of the present invention.

In the first guide 21 a according to another embodiment of the presentinvention, as illustrated in FIG. 13, one side of one end 211 a may bechamfered inward. Particularly, the first guide 21 a has one side of theone end 211 a, which is recessed inward and chamfered to define aconcave space 212 a with a plurality of planes 213. The first guide 21 ais inserted into the battery case 13 so that the recessed one end 211 afaces the inside of the battery case 13.

Also, when the one end 211 a pushes the folding part 136 of the batterycase 13 to the outside, the folding part 136 is inserted into theconcave space 212 a together with the recess induction part 20. Here, anexterior angle θ defined by the plurality of planes 213 of the firstguide 21 a forming the concave space 212 a may be an obtuse angle.

FIG. 14 is a schematic view illustrating a state in which the secondguide 22 is holding the sealing part 134 of the pouch type battery case13 according to an embodiment of the present invention.

When the first guide 21 is inserted into the battery case 13, the firstguide 21 contacts the folding part 136 of the battery case 13. Here,since the first guide 21 has a certain thickness, a portion 1361 of thefolding part 136, which has conventionally formed as the bat ear 2, isused to surround a periphery of the first guide 21. Also, the firstguide 21 pushes the folding part 136 to the outside (S904). Thus, asillustrated in FIG. 14, the folding part 136 may be inserted into theconcave space 212 together with the recess induction part 20. Here, whenthe first guide 21 has an excessively thick thickness, it may bedifficult to insert the first guide 21 through the sealing part 134 ofthe battery case 13. Thus, it is preferable that a thickness of thefirst guide 21 is thinner than that when the battery case 13 is folded.

The second guide 22 holds the sealing part 134 of the battery case 13 tofix the battery case 13 (S905). Particularly, as illustrated in FIG. 14,it is preferable that the second guide 22 may hold each of a firstsealing part 1341 and a second sealing part 1342 from which theelectrode tabs 11 protrude, respectively. The second guide 22 may have aforceps shape to easily hold the sealing part 134 and may hold thesealing part 134 from opposing surfaces.

When the second guide 22 holds the sealing part 134, it is preferablethat the second guide 22 holds the sealing part 134 except for thefolding part 136 as illustrated in FIG. 14, rather than holding theentire sealing part 134. Since the first guide 21 is still inserted intothe battery case 13, when the second guide 22 holds the sealing part upto the folding part 136 in which the first guide 21 is inserted, thefirst guide 21 is not easily pulled out from the battery case 13 later.

When the sealing tool 23 seals the sealing part 134 later, it ispreferable that the second guide 22 continuously holds the sealing part134 to fix the battery case 13. However, if the second guide 22 holds acentral area of the sealing part 134, the second guide 22 may interferewith the sealing of the sealing part 134. Therefore, it is preferablethat the second guide 22 hold an area of the sealing part 134, which isadjacent to the cup part 133 as much as possible.

FIG. 15 is a schematic view illustrating a state in which the firstguide 21 is being pulled out from the pouch type battery case 13according to an embodiment of the present invention, and FIG. 16 is aschematic view illustrating a state in which the sealing tool 23 sealsthe sealing part 134 of the pouch type battery case 13 according to anembodiment of the present invention.

As illustrated in FIG. 15, the first guide 21 is pulled out from thebattery case 13 before the sealing part 134 is sealed (S906). This isbecause the first guide 21 is not sealed together when the sealing part134 is sealed. In addition, heat and a pressure are applied to thesealing part 134 by using the sealing tool 23 to seal the sealing part134 (S907). Here, as described above, since the second guide 22interferes with the sealing of the sealing part 134, the second guide 22holds an area of the sealing part 134, which is adjacent to the cup part133 as much as possible. Thus, as illustrated in FIG. 16, the sealingtool 23 seals the outside of the area of the sealing part 134, which isheld by the second guide 22. Here, in order to firmly seal the sealingpart 134, the area to be sealed has to be as wide as possible.Therefore, it is preferable that the second guide 22 has a thin width asmuch as possible.

As described above, the second guide 22 may hold the sealing part 134except for the folding part 136. On the other hand, as illustrated inFIG. 16, the sealing tool 23 may seal the sealing part 134 up to bothends of the sealing part 134 in addition to the folding part 136. Thisis because when sealing the sealing part 134 except for the folding part136 during the sealing, the internal electrolyte leaks, or externalforeign substances are permeated.

When the first guide 21 is pulled out, and the sealing part 134 of thebattery case 13 is sealed, the folding part 136 is recessed inward as awhole and then sealed by the recess part 1362, which has been insertedinto the concave space 212 of the first guide 21. Thus, the formation ofthe bat ear 2 may be prevented to reduce the error occurring in thedesigned size of the secondary battery 1, and the secondary batteries 1may be easily assembled to manufacture the battery module. Also, sincethe volume of the secondary battery 1 is reduced as a whole by removingan unnecessary space, the energy density to the volume may increase.

Those with ordinary skill in the technical field to which the presentinvention pertains will understand that the present invention can becarried out in other specific forms without changing the technical ideaor essential features. Therefore, the above-disclosed embodiments are tobe considered illustrative and not restrictive. Accordingly, the scopeof the present invention is defined by the appended claims rather thanthe foregoing description and the exemplary embodiments describedtherein. Various modifications made within the meaning of an equivalentof the claims of the invention and within the claims are to be regardedto be in the scope of the present invention.

1-13. (canceled)
 14. An apparatus for manufacturing a secondary battery,the apparatus comprising: a recess induction part configured to allow afolding part folded in a battery case of a secondary battery to berecessed inward so as to provide a recess part when the battery case ofthe secondary battery is folded; a first guide, of which one side of oneend is recessed to define a concave space, wherein, when the batterycase of the secondary battery is folded, the one end is configured to beinserted into the battery case to push the folding part to an outside sothat the recess induction part is configured to be inserted into theconcave space; and a second guide configured to hold a sealing part ofthe battery case so as to fix the battery case.
 15. The apparatus ofclaim 14, wherein the recess induction part includes a plurality ofrecess induction parts configured to move linearly in a directionparallel to a direction toward each other.
 16. The apparatus of claim14, wherein the first guide is inserted into the battery case throughthe sealing part before the sealing part is sealed.
 17. The apparatus ofclaim 14, wherein, when the first guide pushes the folding part to theoutside, the folding part is inserted into the concave space togetherwith the recess induction part to define a recess part.
 18. Theapparatus of claim 14, wherein, in the first guide, the one side of theone end is recessed inward to be filleted.
 19. The apparatus of claim14, wherein, in the first guide, the one side of the one end is recessedinward and filleted to define the concave space with a plurality ofplanes, and an exterior angle defined by the plurality of planes isprovided as an obtuse angle.
 20. The apparatus of claim 14, furthercomprising a sealing tool configured to apply heat and a pressure to thesealing part to seal the sealing part.
 21. The apparatus of claim 20,wherein, before the sealing part is sealed, the first guide is pulledout from the battery case.
 22. The apparatus of claim 14, wherein thefirst guide has a thickness less than a thickness of the battery casewhen the battery case is folded.
 23. The apparatus of claim 14, whereinthe second guide has a forceps shape so that it is configured to holdthe sealing part from opposing surfaces.
 24. The apparatus of claim 23,wherein the first guide has a bar shape.
 25. The apparatus of claim 14,wherein the recess induction part is a pillar.
 26. The apparatus ofclaim 14, wherein the recess induction part is a triangular pillar, asquare pillar, or an elliptical pillar.
 27. A method for manufacturing asecondary battery, the method comprising: accommodating an electrodeassembly, in which electrodes and separators are alternately stacked, ina battery case; recessing a folding part folded in the battery caseinward with a recess induction part to form a recess part when thebattery case is folded; inserting one end of a first guide, of which oneside of the one end is recessed to form a concave space, into thebattery case; pushing the folding part of the battery case to an outsidewith the first guide so that the recess induction part is inserted intothe concave space; fixing the battery case by holding a sealing part ofthe battery case with a second guide; and sealing the sealing part byapplying heat and a pressure to the sealing part with a sealing tool.28. The method of claim 27, further comprising, after the step of fixingthe battery case and before the step of sealing the sealing part, a stepof pulling out the first guide from the battery case.
 29. The method ofclaim 27, wherein the step of inserting the one end of the first guideincludes inserting the first guide into the battery case through thesealing part.
 30. The method of claim 27, the step of pushing thefolding part to the outside includes allowing a portion of the foldingpart together with the recess induction part to be inserted into theconcave space of the first guide.
 31. The method of claim 27, whereinthe first guide has a thickness less than a thickness of the batterycase when the battery case is folded.
 32. The method of claim 27,wherein the step of fixing the battery case includes holding the sealingpart from opposing surfaces with the second guide having a forcepsshape.